EP0244375B1 - Kontaktloser Drehkodierer - Google Patents

Kontaktloser Drehkodierer Download PDF

Info

Publication number
EP0244375B1
EP0244375B1 EP87850067A EP87850067A EP0244375B1 EP 0244375 B1 EP0244375 B1 EP 0244375B1 EP 87850067 A EP87850067 A EP 87850067A EP 87850067 A EP87850067 A EP 87850067A EP 0244375 B1 EP0244375 B1 EP 0244375B1
Authority
EP
European Patent Office
Prior art keywords
recording medium
base plate
detecting element
rotary shaft
rotary encoder
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Revoked
Application number
EP87850067A
Other languages
English (en)
French (fr)
Other versions
EP0244375A3 (de
EP0244375A2 (de
Inventor
Kenzaburou Iijima
Kazuo Kurahashi
Yoshinori Hayashi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yamaha Corp
Original Assignee
Yamaha Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=27293074&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0244375(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from JP61047760A external-priority patent/JPS62204618A/ja
Priority claimed from JP61121127A external-priority patent/JPH07111354B2/ja
Priority claimed from JP61144173A external-priority patent/JPS62299720A/ja
Application filed by Yamaha Corp filed Critical Yamaha Corp
Publication of EP0244375A2 publication Critical patent/EP0244375A2/de
Publication of EP0244375A3 publication Critical patent/EP0244375A3/de
Application granted granted Critical
Publication of EP0244375B1 publication Critical patent/EP0244375B1/de
Anticipated expiration legal-status Critical
Revoked legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/06—Continuously compensating for, or preventing, undesired influence of physical parameters
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M1/00—Analogue/digital conversion; Digital/analogue conversion
    • H03M1/12—Analogue/digital converters
    • H03M1/22—Analogue/digital converters pattern-reading type
    • H03M1/24—Analogue/digital converters pattern-reading type using relatively movable reader and disc or strip

Definitions

  • the present invention relates to a non-contact type rotary encoder provided with a circular recording medium bearing a recorded pattern magnetized along its periphery and secured to a control rotary shaft, a detection head including a detecting element, which is spaced from the recorded pattern on the recording medium, and cancelling means for cancelling influence of fluctuation in clearance between the recording medium and the detection head.
  • a conventional rotary encoder of the above-described type in general has a construction in which a central rotary shaft is coaxially held in a hollow, cylindrical housing and a detection head is fixedly arranged within the housing whilst spacedly facing a recorded pattern magnetized along the periphery of a circular recording medium mounted to the rotary shaft.
  • a recording medium rotates, magnetic field applied to the detection head changes depending on the recorded pattern on the recording medium and, in response to such change in the magnetic field, the detection head generates a series of output signals representative of the recorded pattern on the recording medium. Generation of the output signals is carried out free of trouble as long as the clearance between the recording medium and the detection head is kept constant.
  • Encoders with means usable for cancelling influence of fluctuations in clearance between a recording medium and a detection head are known through US-A-3 268 877, US-A-3 992 576 and IBM Technical Disclosure Bulletin, Vol 3, No 8, Jan 1961, pages 4 and 5.
  • the detection head includes a detecting element
  • the canceling means includes a base plate idly mounted to the rotary shaft, whilst being locked against free axial movement with respect to the recording medium, and fixedly coupled to a housing of the encoder, and the detecting element is mounted to the base plate.
  • a rotary encoder which must be regarded as belonging to the state of the art is shown in Figs.1 through 4 in which a detection head includes a detecting element and a canceling means includes means for holding the detecting element spacedly facing a recorded pattern on a recording medium, means for supporting the holding means for movement with respect to the recording medium, means for urging the holding means to move towards the recording medium and means for ejecting air via the holding means against the recording medium.
  • a circular recording medium 3 eg. a magnetic recording medium
  • a central rotary shaft 2 which is carried in known manner within a hollow, cylindrical housing 1.
  • a recorded pattern is magnetized along the periphery of the recording medium 3.
  • An L-shaped bracket 10 arranged in the housing 1 carries a flexible supporter plate 11 at the distal end of the latter.
  • a casing 12 is coupled to the free end of the supporter plate 11.
  • the casing 12 is open downwards towards the recorded pattern on the recording medium 3.
  • a porous material 13 is packed in the casing 12 for passage of air introduced into the system and the pore ratio of the porous material 13 is preferably in a range from 40 to 60 %.
  • a recess 13a is formed in the bottom face of the porous material 13 as shown in Fig.3 in order to tightly accommodate a detecting element 4, i.e. a magnetoresistive element in the case of this embodiment.
  • Air passages 11a are formed through the supported plate 11 opening downstream in the porous material 13.
  • Air passages 10a are formed through the bracket 10 in communication with the air passages 11a in the supporter plate 11.
  • the air passages 10a are associated with respective tubes 15 for communication with a pressured pneumatic source not shown.
  • a tension spring 16 is interposed between the supporter plate 11 and the bracket 10 in order to constantly pull the casing 12 towards the recording medium 3.
  • the detecting element 4 is pulled by the tension spring 16 towards the recording medium 3, i.e. in the direction of an arrow B opposite to the allow A.
  • the casing 12, i.e. the detecting element 4 is kept unmoved and, as a consequence, the clearance G between the recording medium 3 and the detecting element 4 is always kept constant.
  • a holder block 17 made of a non-magnetic, metallic material is coupled to the free end of the supporter plate 11 and a recess 17a is formed in the bottom face of the holder block 17 in order to tightly accommodate the detecting element 4.
  • a pair of air passages 17a are formed through the holder block 17 whilst opening in the bottom face of the latter.
  • a rotary encoder in accordance with the present invention is shown in Figs.5 and 6 in which, as stated above, the detection head includes a detecting element, the canceling means includes a base plate idly mounted to a rotary shaft whilst being locked against free axial movement with respect to the recording medium and fixedly coupled to a housing and the detecting element is mounted to the base plate. More specifically in Fig.5, a rotary shaft 2 is mounted to a hollow, cylindrical housing 1 via bearings and a recording medium 3, e.g. a magnetic recording medium, is concentrically secured to the rotary shaft 2.
  • a recording medium 3 e.g. a magnetic recording medium
  • a circular base plate 21 is concentrically and idly mounted to the rotary shaft 2 via a bearing 22 so that its free axial movement with respect to the recording medium 3 should be blocked.
  • a recess 23 is formed in the periphery of the base plate 21 in engagement with a stopper pin 24 secured to the housing 1 thereby locking the base plate 21 against rotation. This engagement is deep enough to allow axial movement of the base plate 21 with respect to the rotary shaft 2 without any danger of disengagement.
  • the detecting element 4 is mounted to the base plate 21.
  • the recording medium 3 rotates with the rotary shaft 2 but the base plate 21 is blocked against rotation by the pin-recess engagement.
  • the detecting element 5 generates a series of output signals representative of the recorded pattern on the recording medium 3.
  • FIG.6 A modification of the above-described rotary encoder is shown in Fig.6, in which a leaf spring 25 is secured to the housing 1 in an arrangement such that its free end presses the periphery of the base plate 21 in order to block the same against rotation.
  • vibration of the base plate 21 holding the detecting element 4 is also well suppressed by this spring force.

Landscapes

  • Engineering & Computer Science (AREA)
  • Theoretical Computer Science (AREA)
  • Transmission And Conversion Of Sensor Element Output (AREA)

Claims (3)

  1. Kontaktlos (berührungsfrei) arbeitender Drehstellungsgeber mit einem kreisförmigen Aufzeichnungsträger (3), der ein längs seines Umfangs magnetisiertes Aufzeichnungsmuster trägt und an einer zentralen Drehwelle (2) angebracht ist, einem Detektor- oder Meßkopf mit einem Meßelement (4), das vom Aufzeichnungsmuster am Aufzeichnungsträger beanstandet ist, sowie einem Unterdrückungsmittel zum Unterdrücken des Einflusses von Schwankung im Abstand zwischen dem Aufzeichnungsträger und dem Meßkopf, dadurch gekennzeichnet, daß das Unterdrückungsmittel eine Grundplatte (21) aufweist, die leerlaufend an der Drehwelle (2) montiert bzw. gelagert und gegen Axialverschiebung gegenüber dem Aufzeichnungsträger (3) festgelegt ist, und daß das Meßelement (4) an der Grundplatte (21) montiert ist.
  2. Drehstellungsgeber nach Anspruch 1, dadurch gekennzeichnet daß die Grundplatte (21) mittels eines Stift-Ausnehmung-Eingriffs (23,24) gegen eine Drehung festgelegt ist.
  3. Drehstellungsgeber nach Anspruch 1, dadurch gekennzeichnet, daß die Grundplatte (21) mittels einer Federkraft (25) gegen eine Drehung festgelegt ist.
EP87850067A 1986-03-05 1987-03-04 Kontaktloser Drehkodierer Revoked EP0244375B1 (de)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
JP47760/86 1986-03-05
JP61047760A JPS62204618A (ja) 1986-03-05 1986-03-05 ロ−タリ−エンコ−ダ−
JP61121127A JPH07111354B2 (ja) 1986-05-28 1986-05-28 センサー
JP121127/86 1986-05-28
JP61144173A JPS62299720A (ja) 1986-06-20 1986-06-20 エンコ−ダ用変位検出ヘツド
JP144173/86 1986-06-20

Publications (3)

Publication Number Publication Date
EP0244375A2 EP0244375A2 (de) 1987-11-04
EP0244375A3 EP0244375A3 (de) 1991-02-20
EP0244375B1 true EP0244375B1 (de) 1994-01-26

Family

ID=27293074

Family Applications (1)

Application Number Title Priority Date Filing Date
EP87850067A Revoked EP0244375B1 (de) 1986-03-05 1987-03-04 Kontaktloser Drehkodierer

Country Status (4)

Country Link
US (1) US4768119A (de)
EP (1) EP0244375B1 (de)
KR (1) KR920008052B1 (de)
DE (1) DE3788893T2 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01318917A (ja) * 1988-06-20 1989-12-25 Shicoh Eng Co Ltd 磁気抵抗素子を用いた磁気エンコーダ
JPH0374319U (de) * 1989-11-22 1991-07-25
WO2014136324A1 (ja) * 2013-03-06 2014-09-12 富士フイルム株式会社 レンズ装置及び可動光学素子の位置検出方法

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992576A (en) * 1973-12-13 1976-11-16 Canon Kabushiki Kaisha Floating device for information disc apparatus

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2765459A (en) * 1952-07-14 1956-10-02 Telecomputing Corp Position determining device
US3268877A (en) * 1954-05-26 1966-08-23 Floating magnetic transducing head
US3261968A (en) * 1962-11-23 1966-07-19 Honeywell Inc Angle encoder
FR2199867A5 (de) * 1972-07-13 1974-04-12 Sagem

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3992576A (en) * 1973-12-13 1976-11-16 Canon Kabushiki Kaisha Floating device for information disc apparatus

Also Published As

Publication number Publication date
DE3788893T2 (de) 1994-08-04
US4768119A (en) 1988-08-30
KR920008052B1 (ko) 1992-09-21
EP0244375A3 (de) 1991-02-20
EP0244375A2 (de) 1987-11-04
DE3788893D1 (de) 1994-03-10
KR880000929A (ko) 1988-03-30

Similar Documents

Publication Publication Date Title
US4439699A (en) Linear moving coil actuator
CA1143471A (en) Differential linear velocity transducer
JP3158487B2 (ja) ヘッド支持機構
JPH02263113A (ja) 多回転式軸位置センサー
US4585978A (en) Magnetostrictive actuator with feedback compensation
EP0244375B1 (de) Kontaktloser Drehkodierer
US6421073B1 (en) Device for positioning printing head according to printing substrate thickness
US20080198495A1 (en) Head Actuator Design for a Low Profile Tape Drive
US4031359A (en) Straight line read system
US6326712B1 (en) Magnetic bearing device
US3020767A (en) Linear accelerometer
US4227100A (en) Dual output force motor
CA2036167A1 (en) Optical unit actuator for information recording/reproducing apparatus
US5012372A (en) Head access mechanism for moving heads
JP2788892B2 (ja) 記録装置
US3152485A (en) Magnetic accelerometer
US4237374A (en) Counting system for counting newspapers or the like
GB1603174A (en) Tape speed control apparatus
SU1302147A1 (ru) Индуктивный датчик вибраций
JPS6055224A (ja) 磁気エンコ−ダ
US6307284B1 (en) Positioning apparatus, information recording/reproducing apparatus, and inspection apparatus
JPS62299720A (ja) エンコ−ダ用変位検出ヘツド
US3004222A (en) Compact electrical instrument movement with
US3895387A (en) Vibration de-coupler for use with recording systems
US3166265A (en) Perforated tape vacuum buffer

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): CH DE GB LI

17P Request for examination filed

Effective date: 19880203

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: YAMAHA CORPORATION

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): CH DE GB LI

17Q First examination report despatched

Effective date: 19920402

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): CH DE GB LI

REF Corresponds to:

Ref document number: 3788893

Country of ref document: DE

Date of ref document: 19940310

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: DR. JOHANNES HEIDENHAIN GMBH

Effective date: 19941020

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19950302

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: CH

Payment date: 19950327

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19950426

Year of fee payment: 9

RDAG Patent revoked

Free format text: ORIGINAL CODE: 0009271

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT REVOKED

27W Patent revoked

Effective date: 19950703

GBPR Gb: patent revoked under art. 102 of the ep convention designating the uk as contracting state

Free format text: 950703

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL